


Caught Blue Handed

by poubelle_squelette



Series: Fuck Me Eight Ways to Sunday [4]
Category: Undertale (Video Game)
Genre: Don't get caught kink, F/M, Guilt, Hand Jobs, Kinktober, Masturbation, Plot What Plot/Porn Without Plot, Reader-Insert, Sans is a gross gremlin, Shame, Vaginal Sex, Verbal Humiliation, im trash for writing this, oh my god they were roommates, reader is female
Language: English
Status: Completed
Published: 2018-12-13
Updated: 2018-12-13
Packaged: 2019-09-17 19:10:54
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,241
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16980174
Author URL: https://archiveofourown.org/users/poubelle_squelette/pseuds/poubelle_squelette
Summary: It started out as an accident. He had been lazily masturbating in his room when you came home from work. He was too close to stop, so he just kept stroking in the hopes you wouldn’t hear him. He promised himself to make a note of your schedule so this wouldn’t happen again.But the thought was already there. The nagging thrill of almost getting caught.





	Caught Blue Handed

Sans was a terrible person.

He was never supposed to take it this far.

You were just too damn irresistible and he had no self-control.

It was only supposed to be a one-time guilty pleasure.

He stroked his cock, a bead of precum forming at the tip. 

It started out as an accident. He had been lazily masturbating in his room when you came home from work. He was too close to stop, so he just kept stroking in the hopes you wouldn’t hear him. Sans was as quiet as a mouse, biting down on his pillow to stop himself from making any noise. Once he orgasmed, he promised himself to make a note of your schedule so this wouldn’t happen again.

But the thought was already there. The nagging thrill of almost getting caught.

For a while, he forgot about the incident entirely. Then, one day he thought he heard the door unlock and the thought of getting caught sent shivers down his spine. He was excited at the thought of someone walking through the front door and catching him doing something so dirty and private. 

It was just a fantasy he had. When he masturbated, he sat splayed out on his bed, facing the doorway. He imagined someone opening his door and staring. He imagined the shock on their face from seeing him like this. Sometimes it was a neighbor asking for sugar, or a pizza delivery guy, or a stranger Sans concocted. 

But most of the time, it was you he was fantasizing about. 

Well, he wasn’t fantasizing about _you_ in particular, at least…it wasn’t at first. It just made the most sense. You lived here and were the most likely to accidentally drop in on him during a…session. He could clearly imagine exactly how your face would be, how you’d scold him for leaving his doorway unlocked or, if he dared, _open_ for you to see. Shaming him for it, even.

Just his imagination was enough for a while, but imagining getting caught wasn’t enough. Sans knew when you’d be in or out of the house, so he always made sure to take care of himself when he knew he had a few hours.

And then when he knew he had one hour.

And then when he knew he had thirty minutes.

And then fifteen.

It was a race between the cock and the clock. Could he finish before you opened the door? How far could he push this?

You almost caught him, once. Right as he was leaving his room for the bathroom, jizz still coating his hand, you walked through the front door. Sans immediately shoved his gross hand into his pocket and nearly had a second orgasm. You were definitely eyeing him suspiciously, because he was acting totally suspicious, and he had to quickly maneuver himself away so you wouldn’t see the giant boner he was sporting. 

After that moment, he couldn’t stop fantasizing about you or stop replaying that interaction in his head. You were so close to figuring out what he was doing. 

He wasn’t sure if the crush developed because of the kink or if it had always been there and was just now manifesting itself in the most inconvenient of ways. Either way, you were at the forefront of his mind when he touched himself. 

He knew it was weird.

And wrong.

And probably creepy.

But he couldn’t help himself. He took notice of you when you sat a little too close or smelled a little too nice or wore a shirt that was just a little too snug. You leaned on him once when the two of you watched a movie and Sans spent two hours in the shower that night, imagining touching himself under the blanket with you _right there_.

Sans knew in your eyes, the relationship the two of you have is platonic. This only served to turn him on even more when he imagined you catching him fapping to your image. You’re supposed to be his _friend_ and now not only was he caught in the act but it was also _you_ , someone he shouldn’t ever think about sexually.

Sans started pushing his luck further and he left the door to his bedroom unlocked. But you would never barge into his room unannounced. You were too nice and accommodating. You would always knock and wait for him. 

That’s what led him to this. His door was ever so slightly ajar, a daring move from Sans, although he knew he had quite a bit of time before you were supposed to come home. He stroked the head of his cock again, his breathing slightly haggard now.

Sans closed his eyes and pictured you walking by his bedroom, spotting him openly vulnerable and unable to take your eyes off him. He called out your name as he tightened his grip. God, he could just see you there in the doorway, could picture your eyes flick from his dick to his eyes. He moaned your name this time again and used his other hand to graze the inner part of his ribcage. 

If he concentrated hard enough, Sans could even hear your voice say:

“Oh my god!”

“hrnk!”

Sans opened his eyes and froze, hand still on his shaft. There you were, in his doorway, like he’d been picturing for the last several weeks. Your cheeks were starting to stain red, but you were also frozen in place.

Cold shame washed over Sans as he scrambled to cover himself with a blanket. 

“Oh my god, I’m so sorry.”

“shit i’m sorry.”

You covered your eyes and turned away. “I didn’t realize that’s what you were doing!” you squeaked.

“i thought you were gone, i’m sorry.”

“But you called for me!”

“ _i thought you were gone_ ,” Sans reiterated, skull hot and sweaty.

“But you called for…me. You…” you lowered your hands. “You shouted my name as…”

The moment that Sans has been fantasizing about for the last few weeks was happening now, in front of him. He could feel you starting to put the pieces of the puzzle together. This was wrong, so terribly wrong. He squeezed his eyelids shut as another bead of sweat ran down his face. Sans was realizing that fantasy and reality were two very separate things.

And reality was, unfortunately for Sans, so, so much hotter if his hard-on was anything to go by.

You slowly turned, eyes briefly glancing at the lump in the blanket before locking with his.

“As you were thinking of me,” you said. A bold statement, straight to the point and with your face steady, looking directly at him. You left no room for questions or back-pedaling. You knew.

The shame was too much to bear and Sans immediately came, semen spurting out from the tip of his cock and spilling onto the blanket. A dark spot bloomed and spread as you stared him down. Sans broke eye contact first, unable to look you in the face now that you’ve seen what he’s done. He lowered his head, consumed by guilt. He heard his bedroom door close and your footsteps walk down the hall to your own room. You had left. Definitely disgusted.

Sans lay there, underneath his cum soaked blanket, and replayed the moment in his mind. He grimaced, berating himself for actually getting caught, which was never a part of his plan.

Ugh.

He supposed it could’ve gone worse.

He balled up the blanket and threw it onto the floor before pulling up his shorts. Welp. He wasn’t sure how he could come back from this one. 

You started to avoid Sans like the plague. Whenever he entered a room you were already in, you got up and disappeared to another part of the house. If you entered a room he was already in, you would immediately turn around and forget about whatever you needed. You mostly stayed in your bedroom, except when you left for work. You could cut the tension in the apartment with a knife.

Sans didn’t touch himself for nearly two weeks after the incident, for fear that you would actually catch him in the act again. He felt so awful and guilty about making things in the house awkward.

But Sans couldn’t hold out forever. Enough time had passed and he knew you wouldn’t exactly approach his bedroom after what had happened. It was the middle of the night and Sans knew you went to bed. Your room was down the hall, so as long as his door was closed and he was quiet, Sans could quickly rub one out without you knowing.

Sans lay on his bed, dick out and imagination ready. He wrapped his hand around it and began to pump slowly, biting the collar of his t-shirt to keep himself from moaning out your name again. He pictured that moment when you walked through the door, your eyes flickering between his erection and his face. The shame. The absolute shame and humiliation he felt in those seconds. 

“You just couldn’t help yourself, huh?”

Sans inhaled sharply. No. No. No no no no no no no. This wasn’t happening to him again. He very slowly opened his eyes.

Your silhouette was in the doorway. It was too dark to see your face, but you were definitely in the doorway. 

Before Sans could start apologizing again, you continued, “Didn’t even lock your door. It’s almost like you wanted to get caught again.” You took a step forward. “Am I wrong? You’ve been cagey lately, but you still didn’t wait for me to leave the house.” Another step forward. “You wanted me to come in while you were doing this, didn’t you?”

Sans wanted to sink into his mattress and die.

“no, no, i wanted to-” whatever Sans was going to say died on his tongue because you finally reached the edge of his bed and Sans could see that you were in nothing but your bra and panties. “…holy shit.”

You crossed your arms and tilted your head the side. “ _Didn’t you_?” you repeated, an edge to your voice.

“…yes.”

“Disgusting.”

Sans shuddered as his cock twitched.

“You don’t even have the decency to pretend you’re ashamed by how horny you are.” You climbed onto the bed and palmed his erection, going agonizingly slow. “How long have you been getting off to this? To me?”

Your hand tightened. God, human skin felt so nice wrapped around it. Sans let out a shaky moan. “ah…a..ahh, a month or so.”

“Pathetic.”

Your strokes were slow. You rubbed your thumb along the head, wiping a bit of precum along the tip. Sans trembled underneath your touch. He closed his eyes again and rode out the feeling of your hand sliding up and down his cock. His skull burned, but he was painfully turned on by the situation.

“You’re getting off on this, aren’t you?” you sneered. “This is what you’ve always wanted, isn’t it?”

“…yes,” Sans whispered.

“ _Yes_ isn’t good enough. Tell me every filthy, dirty, disgusting fantasy you’ve ever had of me. The things you pictured in the privacy of your bedroom. Every shameful secret that’s ever crossed your mind. I won’t let you cum until you tell me.”

To make your point, your hand stilled. Sans tried to buck into you, but you used your other hand to push him down into the mattress.

“You’ve been bad,” you said. “I’m your roommate. I’m your friend.”

Sans swallowed. The air was too hot and he was sweating bullets. He needed friction against his dick so badly, but you were clear.

He can’t cum until he tells you.

Shakily, he started speaking, his voice strained, “i get off on you catching me, catching me doin…this. i’ll start when i know i only got fifteen minutes. i keep my door unlocked because i wantcha to open it. i want you to degrade me for it. call me gross. call me disgusting. this is the worst thing i've ever done. it's hot because you’re my roommate. because you’re my friend.”

You rewarded his confession by resuming your handjob. Sans couldn’t help but utter out, “fuuuck. thank you.”

“You are bad. And disgusting. You wanted me to catch you like this? As if I would ever degrade myself to sleeping with you.”

“i…i know,” Sans choked out. You tightened your grip and he whined, unable to hold himself back. “i used to picture strangers but you were too irresistible. too soft. too unattainable. too good for me. you’d wear clothes that clung close to your body and i dreamed about takin them off.”

Your pace quickened. “Then what? Hmm? What happens after I catch you?”

“mostly you’re just disgusted as you f-force me to masturbate in front of you,” Sans admits. “t-taunting me about…it.”

You bite your lower lip as you removed your hand from him. Sans cried out in protest. You grabbed his hand and placed it over his dick. “Do it, then. Touch yourself. I’m right here in nothing but my underwear.” You reached behind you and unclasped your bra, letting it fall off you. You picked up the garment and threw it onto the floor. 

Sans’s fingers shook as he started stroking himself, looking anywhere else in the room but at your exposed chest. 

“Go on, get a look at them. I bet you’ve been picturing them all along.”

“n-no.”

“Tell the fucking truth, Sans.”

“yes.”

Sans took his chance as looked up. Your naked breasts finally in front of him, the soft round flesh begging to be touched, nipples pert and rosy. He watched as they jiggled as you readjusted yourself on the bed, straddling his legs whilst standing on your knees. He wanted to hold them in his own hands, squeeze the fat and rub his thumb against your nipples.

“Rub the head, nice and slowly,” you commanded. “Let your hand graze the shaft. I bet you want to lay your filthy hands all over me right now. I bet you’re dreaming about cupping my breasts instead of your dick.”

You scoffed at him as you watched him jerk off. 

The room was silent except for the _schlick-schlick-schlick_ sound. This only further cemented Sans’s shame and embarrassment as you watched him lose any shred of dignity he had left in him.

“Faster,” you commanded. “Tighter.”

Sans did what you asked, moaning out your name as he did. His body trembled as the pace of the _schlick-schlick-schlick_ increased and his bones started rattling.

His was getting close, so close. He rested his free hand on his ribcage and gently scratched the surface. The pressure was building and his vision started darkening. This felt so wrong and so right and the way you were looking at him only served to turn him on even more. He moaned your name again as he increased the pressure and-

“Stop.”

Against his will, Sans stopped.

“…please,” was the only thing he could force out. “please let me finish.”

“No.”

Sans wanted to cry, having gotten so close. Just a few more strokes and he would’ve been done. His cock throbbed in his hand, willing for him to continue. 

“You’re not done yet. What else do you imagine, hmm? After I make you masturbate, then what?” 

Desperate, Sans began rattling off everything that he’d thought of in the last month, “i think about you catching me in the shower, i think about you in the shower, wet and willing. when we watch tv together in the living room i consider touching myself under the blanket to see if you’d notice. i think about you degrading me out in public, in private, in front of strangers, in front of friends. i want to touch you, feel you all warm and wet. i imagine you giving me pity sex before leaving me drenched in my own cum. i-”

You pulled down your underwear and Sans let his mouth click close. You threw it to the ground where your bra was and straddled yourself over his boner. 

“you…uh…”

“Shut up,” you said, rubbing yourself against his tip. “You want pity sex? Then you better fucking remember this moment because it’s the only time I’d ever let the likes of you touch me this way.”

You lowered yourself and began moving quickly. This felt so much better than Sans ever imagined. You were so slick and warm, his dick glided in and out so easily. He let his head fall back against his pillow and let out another moan. 

“Is this what you wanted?” you asked as you fucked him into the mattress. “Even making me do all the fucking work while you lay back. I don’t know why I’m surprised that you’re such a lazy lover.”

Sans couldn’t find it in himself to answer because getting fucked by you was rendering him speechless. Velvety and soft and quick and hard. The pressure was building again, a tight coil in his center. He knew, _he knew_ , he wasn’t going to last much longer.

“p-p-please,” he stuttered. “p-please let me.”

“Do it,” you said, “Cum in me like you’ve always dreamed about like the absolute perverted, piece of shit you are.”

The snide tone of your voice mixed with your harsh and judgmental words tipped Sans over the edge. He gripped the bedsheets as tightly as he could as ropes of sticky cum spurt out. He moaned, loud and long, as he bucked into you. You clenched tightly, giving him extra friction as the last bit of his semen came out.

His dick disappeared and he watched as the blue liquid spilled out of you and onto his pelvis.

For a moment, neither of you said anything.

God, this was it, wasn’t it? You were packing your bags first thing tomorrow and leaving him for being a gross piece of trash. Sans swallowed, unsure of what to say.

To his surprise, you rolled off of him and laid beside him on the bed. 

“That was harder than I thought it’d be,” you said. “I wasn’t sure how long I could keep that up. I really thought I was going to botch it and accidentally say something sappy.”

…

“huh?”

“It was so hard to be mean like that. I really thought you were going to tell me to stop or teleport away or something.”

Sans stared, absolutely flabbergasted by your change in demeanor. “what?”

“Well I mean…” you shifted so you could look him in the eye. “I guess when I caught you the first time I sort of realized what you were into and…uh…well, I don’t know. I didn’t think you liked me like that so when I found out…I dunno, I thought I could surprise you.”

“it worked,” Sans said, still not believing that you were still here.

You smiled again and scooched a little closer. “I know!” you said, clearly proud of yourself.

“…so. now what?”

You hmm’d and then got out of the bed. You offered your hand and said, “I could use a shower. I promise you I’ll be _wet and willing_.”

Hearing his own embarrassing confession be thrown back at him sent a pang of arousal through him. Sans still couldn’t quite believe that he wasn’t dreaming, but he took your hand and followed you to the bathroom, eager to see what you’d tease him with next.

**Author's Note:**

> im trash.


End file.
